Transponder and method for a wireless data transmission

Abstract

A transponder and a method for wireless data transmission is provided. The transponder comprises an input circuit with input terminals for connecting an antenna coil for data transmission to a base station by means of inductive coupling, a first controllable switching means, at least one resistor, which is looped in series with the first controllable switching means between the input terminals of the input circuit, and a controller which is designed in such a way that it connects through the first switching means as soon as a voltage applied at the input terminals falls below a first settable threshold value, and again interrupts it as soon as the voltage applied at the input terminals for a settable duration is above the first settable threshold value and/or above a second settable threshold value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 illustrates a passive transponder with an input circuit for connecting an antenna coil for inductive coupling with a base station; and

FIG. 2 is a timing diagram during a data transmission from a base station to the transponder of FIG. 1.

Claims

1. A transponder comprising an input circuit having input terminals for connecting an antenna coil for facilitating data transmission to a base station by inductive coupling;a first controllable switch;at least one resistor that is looped in series with the first controllable switch between the input terminals of the input circuit; anda controller that connects the first controllable switch when a voltage applied at the input terminals falls below a first settable threshold value and interrupts the first controllable switch when the voltage applied at the input terminals for a settable duration is above the first settable threshold value and/or above a second settable threshold value.

2. The transponder according to claim 1, wherein the transponder is a passive transponder.

3. The transponder according to claim 1, wherein the first controllable switch is a transistor or a MOS transistor.

4. The transponder according to claim 1, wherein the input circuit processes frequencies within a frequency range of 50 kHz to 250 kHz.

5. The transponder according to claim 1, wherein the input circuit for the data transmission to the base station comprises a modulation unit with a controllable voltage limiting unit, which limits the voltage applied at the input terminals to a first settable maximum value or to a second settable maximum value.

6. A method for wireless data transmission via inductive coupling between a base station and a transponder, which has an input circuit with input terminals for connecting an antenna coil, the method comprising: turning on a resistive load that is provided between the input terminals when a voltage applied at the input terminals falls below a first settable threshold value; andturning off the resistive load when the voltage applied at the input terminals for a settable duration is above the first settable threshold value and/or above a second settable threshold value.